OMNIVOROUS ANNELIDS, &c. 263 



All wheel-animalcules, however, are not entirely limited, as 

 regards food -supply, to what is brought by ciliary currents. 

 Some of them (fig. 470), such as the beautiful Crown Rotifer 

 (Stephanoceros], possess a number of pointed projections from 

 the head - region, which are actively used to surround small 

 animals or other food substances, and their efficiency may be 

 increased by the presence of slender bristles, as in the Flower 

 Rotifer (Floscidarid). The mouth of a wheel -animalcule leads 

 into a funnel-shaped pharynx lined with cilia, and this again is 

 continuous with a powerful muscular gizzard (mastax) imbedded 

 in the walls of which are hard jaw-like pieces used for chewing. 

 In many cases these jaws can be protruded from the mouth and 

 employed for seizing food, even, it may be, for attacking other 

 rotifers with a view of adding them to the bill of fare. 



